THE EFFICIENCY OF UTILIZATION OF ENERGY AND NITROGEN IN YOUNG SAMBAR (CERVUS UNICOLOR) AND RED DEER (CERVUS-ELAPHUS)

Two experiments each with two rates of feeding (maintenance and twice maintenance) were conducted during summer 1993/94 (Expt 1) and summer 1994/95 (Expt 2), at Massey University, New Zealand. Four sambar and f our red deer, including stags and hinds aged 10-14 months, were used i n each year. Animals were fed a pelleted diet (total N 30 g/kg DM; NDF 247 g/kg DM). Digestibility and nitrogen (N) balances were determined using deer metabolism cages, whilst methane production and heat produ ction were determined using open circuit respiration calorimetry, with measurements made on each deer at both rates of feeding. Digestibilit y and metabolizability of energy were greater for sambar than for red deer in Expt 1 but not in Expt 2. Nitrogen retention, expressed as a p roportion of N intake, was similar for sambar and red deer. Metaboliza ble energy required for maintenance (MEm) was 474 kJ kg W-0.75 d(-1) f or sambar deer and 567 kJ kg W-0.75 d(-1) for red deer, whilst the eff iciency of utilization of ME above maintenance (k(g)) was similar for sambar deer and red deer. These studies indicated that the sambar deer had lower rates of maintenance heat production than the red deer, whi ch may explain the sambar's superior feed conversion measured in previ ous experiments. However, the two species utilized nitrogen with simil ar efficiency, when fed a high quality ration.